<?php
    include('sql.php');
    $mlzyl = "select * from mlzyl";
    $mlzyl_result = mysqli_query($link,$mlzyl);
?>
<select name="zylb" class="index_input">
    <option value="0">请正确选择门类、专业类</option>
    <?php while ($mlzyl_row = mysqli_fetch_array($mlzyl_result)) { ?>
    <option value="<?php echo $mlzyl_row['mlzyl']; ?>"><?php echo $mlzyl_row['mlzyl']; ?></option>
    <?php } ?>
</select>